Is Micro-Ultrasound Ready to Become the New Standard for Prostate Cancer Diagnosis? Comment on Saitta et al. SIU-ICUD: Comprehensive Imaging in Prostate Cancer—A Focus on MRI and Micro-Ultrasound. Soc. Int. Urol. J. 2025, 6, 39

Prostate cancer remains one of the most prevalent malignancies among men worldwide, with early and accurate diagnosis being critical for improving outcomes. In this journal issue, Saitta et al. have comprehensively described the current status of using magnetic resonance imaging (MRI) or micro-ultrasound for prostate cancer diagnosis [1]. MRI has established its role in the diagnosis of prostate cancer and is recommended as the first-line investigation for patients with elevated serum prostate-specific antigen (PSA). However, the availability and cost of MRI in some areas, along with potential contraindications in certain patients, may hinder its application.

As summarised in the paper, the development of high-resolution micro-ultrasound has emerged as a promising real-time imaging modality [1]. While the initial results were encouraging, some limitations must be addressed before it can be widely adopted as a standalone diagnostic tool.

Similarly to the initial development of multiparametric MRI and the Prostate Imaging Reporting and Data System (PI-RADS) system in prostate cancer diagnosis, the assessment heavily relies on individual experience, necessitating the standardisation of reporting and training in this field. Zhou et al. reported that the inter-reader agreement on the suspicious areas in micro-ultrasound was lower than that for MRI [2]. Therefore, there is a need for greater standardisation of the reporting system and enhanced training programmes to facilitate the widespread usage of micro-ultrasound.

Moreover, due to the intrinsic nature of transrectal ultrasound, the imaging of the prostate may be challenging, particularly in individuals with a larger prostate size and prostatic calcification. Also, ultrasound may not be able to assess the lymph node status, as compared to MRI.

While MRI for prostate diagnosis may be expensive in certain areas, MRI facilities are now generally accessible in most hospitals. Even in centres lacking a specific fusion system, the cognitive fusion of MRI imaging using existing ultrasound systems remains a viable option, yielding comparable results to image-guided fusion [3]. However, micro-ultrasound currently requires a specific machine, which might limit its utilisation, particularly in budget-constrained centres.

Micro-ultrasound is a valuable addition to the prostate cancer diagnostic toolkit, particularly where access to MRI is limited. However, current evidence suggests that it should complement—rather than replace—multiparametric magnetic resonance imaging (mpMRI) in most settings. Future directions should include the refinement of the reporting system, the incorporation of artificial intelligence-assisted interpretation, and standardised training programmes. Until these gaps are addressed, micro-ultrasound can remain a valuable tool in prostate cancer diagnosis.